Apparatus for drawing tubes.



'1. -w. OFFUTT.

APPARATUS FOR DRAWING TUBES.

APPLICATION FILED JULY6. 1915.

1,175,890. Patented Mar. 14, 1916.

3 SHEETS 'SHEPT l.

FIG.1

WITNESSE ENVENTOR J. W. OFFUTT.

APPARATUS FOR DRAWING TUBES.

APPLICATION FILED JULYG. l9l5.

Patented Mar. 14, 1916.

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3 SHEETS-SHEET 3- Patented Mar. 14, 1916.

HNMENTOR nsw v.

J. W. OFFUTT.

APPARATUS FOR DRAWING TUBES.

APPLICATION FILED JULY 6, 1915.

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@213! ESSES JOHN W. OFFU'IT, 0F ELLWOOD CITY, PENNSYLVANIA, ASSIGNOR TO THE SHELBY STEEL TUBE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Mar. 14,1916.

Application filed July 6, 1915. Serial No. 38,336.

To all whom it may concern:

Be it known that 1, JOHN W. Orrn'r'r, a citizen of the United States, and resident of Ellwood City, in the county of Lawrence and State of Pennsylvania, have invented certain new and useful Improvements in Apparatus for Drawing Tubes,-of which the following is a specification.

My invention relates to apparatus used in the manufacture of drawn tubes and more particularly cold drawn seamless tubes.

In one method of making cold drawn tubes used heretofore it has been the practice to pull the annular or hollow tube blanks through the drawing dies by means of a draw chain, tongs, or equivalent fastening means employed to detachably connect the front or forward end of the blank to the draw chain in pulling the blank through the reducing die. It has also been the practice to draw hollow tube blanks through the die with a mandrel inserted within the hollow blank, the mandrel forming an internal support for the wall of the blank and enabling an increase in the percentage of reduction in the cross section of the blank in each drawing step over what is practicable in drawing hollow blanks Without a supporting mandrel. In this latter method, which is the one in general use, it is necessary after the completion of each reduction in cross section, 01- cold drawing step, to pass the drawn tube blank between the rolls of a reeling machine in order to loosen the mandrel therein, as the internal diameter of the blank is lessened in being drawn through the die to such an extent as to force the inner wall of the blank into tight holding engagement with the mandrel.

One object of my invention is to provide apparatus for drawing tubular blanks or tubes having novel means whereby the blanks are expanded, the mandrels are loosened therein simultaneously with the blank drawing operations, and the tubes are stripped from the mandrel.

Another object of myinvention is to provide tube drawing apparatus having improved means whereby the extent of the reduction in cross sectional area of the tube blanks in any one pass may be made materially greater without danger of the tube blank breaking or pulling apart in the drawing operations.

Another object of the invention is to provide apparatus for'drawing tubes having improved means whereby one part of the tube is expanded while another part is being cold drawn, and the necessity of reeling the tube to loosen the tube and release the mandrel at the completion of each drawing step to which the blanks are subjected, in a separate and independent reeling operation, is avoided and overcome.

A further object of my invention is to provide apparatus for drawing tubes of improved construction having novel means enabling the tube blanks to be pushed through the reducing die instead of being pulled in the cold drawing operations.

A further object of the invention is to provide tubev drawing apparatus having improved means whereby the tubes and mandrel are held and prevented from bending when pressure is applied to the end thereof to push the tube through the drawing die.

A still further object of my invention is to provide tube drawing apparatus of-improved construction having novel means whereby the die and die holder and the stripping mechanism are adjustably positioned relative to the chain support of the tube drawing apparatus in such manner as enables tubes of a variety of sizes to be drawn cold with the tube drawing apparatus.

Referring now to the drawings forming part of this specificatiom'Figure 1 is a plan showing tube drawing apparatus constructed and arranged and having a reeling machine and a stripper mechanism applied for use therewith in' accordance with my invention. Fig. 2 is a longitudinal side elevation, partly in section, ofthe tube drawing apparatus shown in Fig. 1. Fig. 3 is a sectional end elevation of the apparatus shown in Figs. 1 and 2, the section being taken on the line III-III of Fig.2. Fig. l is a plan showing a detail in the ('sonstruction of the fasteningused in locking the guiding cover forming part of my improved apparatus in closed or tube drawing position. Fig. 5 is a sectional side elevation showing a detail of the fastening by which the mandrel is detachably secured to the draw chain of my improved apparatus. Fig. 6 is a side elevation, partly in section, showing one form of reeling machine adapted for use with my apparatus in reeling tubes to loosen the mandrel therein simultaneously with each drawing operation. Fig. 7 is an end elevation of the-apparatus shown in Fig. 6. Fig. 8 is a plan showing a modification in the construction of tube drawing apparatus made in accordance with this invention. Fig. 9 is 'a' longitudinal side elevation of the tube drawing apparatus shown in Fig. 8.

In the accompanying drawings the numeral 2 designates a lengthwise horizontal draw chain support having a longitudinal recess or slot 3 formed in its upper surface by the ribs or flanges 4: and 5 on the long1- tudinal side edges of the support 2, and positioned to slide within the so-formed recess 3 is a draw chain formed of alternate double links 6 and single links 7 which are pivotally connected at the ends thereof hv means of pins 8.

One or. more special chain links 9, depending upon the length of the endless chain, are provided. on the apparatus of Figs. 1 and 2, the link 9 having a connecting member 10 with a recessed slot 11 in its upper face by which the end of the mandrel l2 usedwith my improved apparatus is detachably secured to the draw chain. A

similar link 9 is employed on the rear end of the draw chain of Figs. 8. and 9 in attaching the mandrel 12 to the chain, and this link is connected by a special link 13 (see Fig. 5) to the screw. threaded outer end of the reciprocating piston rod 14 to'operatively connect the draw chain to the reciprocating chain operating mechanism forming part of the apparatus of Figs. 8 and 9. The rear end of the mandrel 12 is provided with a flange or T head 15 and in connecting the mandrel to the draw chain, this flange is seated in the recess or slot 11 in the upper face of the connecting member 10 of the link 9. The removable wearing plate 16,

removably secured in the bottom of the Iongitudinal recess .3 and contacting with the reciprocatory draw chain within the slot or recess 3 prevents wear on the chain support. The single links 7 in the draw chain have a V-shaped groovel7-extendin len hwise on one edge (see/Fig. 3), the tu e blanks 18 being supported in these grooves during the tube drawing operations, and the sides of the grooves 17 assisting in maintainin the tube blank in lengthwise alinement and preventing sidewise bending when power is applied to the chainto push the blank through the drawing dieof the tube drawing apparatus.

Instead of making the chain support 2 to extend in a-flat horizontal plane as shown, it may curve rearwardly and upwardly to a slight extent, or the rear end of the chain support may be elevated somewhat so that when a hollow blank or tube 18 is placed on the chain, the ends of the blank will first engage the chain, and when pressure is applied to the end of the tube blank the tendency of the blank to sag or deflect downwardly in the middle thereof, due to its weight when supported at its ends, will influence and determine the direction in which the blank will bend to the slight extent allowable when pressure is applied to force the blank through the drawing die. In this way the tube blank 18 will be deflected downwardly into engagement with the side surface of the V-shaped recess 17 in theupper surface of the single links 7 of the draw chain. I

Hinged to a series of bracket bearings 19 which are secured to the rib or flange 4 on one side of the chain support 2,-is a'pivoted guiding cover 20 having a closed top and open bottom forming a longitudinal recess 21- therein; the sides 22, 22, of the guiding cover having inturned flanges 23 on the lower edges thereof. Supported within the recess 21 by the flanges 23, 23, is a removable wearing plate 24 having a V-shaped groove 25 in its lower face. This plate, which may be made in sections when desired, is positioned in the cover 20 so that the side walls of the V-shaped groove 25 engage with the tube or blank 18 being drawn during the tube drawing operations.

A shaft 26 is employed to pivot the guiding cover 20 on the bracket bearings 19, the cover being keyed to the shaft 26 so as to be rocked thereby, and the shaft 26 having an operating lever 27 thereon which is connected by a link 27 to a suitably located in the upper. edge of the flange 5 forming one side of the recess 3 in the chain support 2. Asliding bar 30 having a series of notches 31 in one edge thereof is secured on top of the flange 5, a series of slotted openings 32 being provided in the bar for the cap bolts 33 by which the 'bar 30 is movably secured on the flange 5 (see Fig. 4). A

handle 34 on the rear end of the bar 30 provides means for moving the bar lengthwise to shiftthe notches 31 in one edge thereof into and out of registering position above the lugs 28 on the swinging cover 20 so that when the bar 30 is moved to bring the notches 31 into registering position above the lugs 28 the guiding cover can be swung into and out of its lifted position, or that shown in dotted lines in Fig. 3. When the bar 30 is moved to bring the notches 31 araaseo into the position relative to the lugs 28 shown in Fig. 4, the guiding cover. 20 is fastened in its closed position .(that shown in full lines in Fig 3).

At the rear or discharge end of the chain support 2 is a reeling machine having reeling disks or rolls (see Fig. 6) by which successive portions in the length of the tube blank .18 are reeled upon emerging from the drawing die 52'to expand and loosen the drawn portions of the blank from the mandrel 12, which is within the tube blank in. the drawing operation. This reeling machine as shown has a base 37 with a vertically adjustable support 38 secured in guides 39 thereon. The support 38 is ad- 11..

justed and held in adjusted position on the base 37 by means of the vertical shaft 40, the screw threads 41 on its lower end engaging the internally threaded hole 1n the bottom of the hollow base 37. The flange or collar 42 at an intermediate point in the length of the shaft is provided in its periphery with a series of holes 43 to enable the shaft to be turnedby means of a bar 1nserted through the transverse opening 44 in the'base into the holes 43 in adjusting the support on the base. The shaft 40 is mounted in bearing 45 in the base, and its upper end projects into the opening 46 in the bottom of the vertically movable support 38.

The upper face ofthe support 38 is provided with bearings 47, 47, in which the hollow trunnions'48, 48, of the rotating casing or body 49 of the reeling machine are mounted. Positioned so as to be relatively adjustable within the body 49 of the reeling machine is the set of three rotating reeling disks 35. The axes of these reeling disks (as shown in Fig. 6) extend at an angle to the axis of rotation of the body 49 and the periphery of the disks 35 engages with the tube blank 18 being reeled. .The periphery of the body 49 is crowned for the endless" driving belt 50 which rotates the body 49 and the reeling rolls or disks 35 about or around the tube 18. It should be noted that the tube blank 18 does not rotate while being reeled-butthat the body 49 of the reeling machine rotates around the tube blank, and that the disks 35 are caused to rotate each on its own axis bv frictional engagement with the outer surface of the tube blank 18, this construction making it possible to simultaneously draw and reel different portions of the tube blank.

To enable tube-blanks of various diameters to be drawn and reeled with my improvedapparatus the die block 51 for the drawing die 52 is mounted in the die seat of the die block on the reeling machine support 38 so that the axis of the opening through the die 52 will always be in al1ne- .alinement with the reeling machine.

. To prevent the reeled tubes being pulled backwardly between the disks of the reeling machine with the backward movement of the mandrel when the mandrel 12 is being retracted or withdrawn from the drawn and rolled tubes, a stripper is provided on the support 38 onthe discharge side of the reeling machine. This stripper comprises a stripper guide 53 having vertically movable stripper plates 54 in the slot or gro'ove' 55 of the' stripper guide 53. The stripper guide 53 has a semicircular slot 56 in its lower edge, of a diameter which neatly fits the cylindrical mandrel 12, when the mandrel is being withdrawn;

In the construction shown in Figs. 1 and 2, an endless draw chain formed of the links 6 and 7 is employed, the chain, which is reciprocatecl in the tube drawing operations, passing over driving sprocket wheels 57 and 58 located at the opposite ends of the chainsupport 2. The sprocket wheels, both of which are positively driven, are secured on horizontal shafts 59 and 60 mounted in suitable bearings below the cha n support 2, the sprocket wheel 57 proectmg upwardly through an opening 61 in the bottom of the support, into the recess 3 1n the chain support, and the sprocket wheel 58 projecting upwardly into the recess 3 1n a similar manner at the opposite end of the support 2. The chain support 2 of Figs. 1 and 2 is secured on hollow standards 62 and one end of the support 1s secured on the ledge 63 on one side of the reeling machine base 37. The bottom strand of the endless draw chain of Figs. 1 and 2 extends through transverse openlngs 64 in the hollow standards 62, and antifrlctlon rollers 65 rotatably mounted with- 1n the hollow standards are provided below the transverse openings 64 to support the bottom strand of the endless chain (as 1s clearly shown in Fig. 2). sprocket wheels 57, 58, are positively rotated, each of the sprocket shafts 59 and 60 having a bevel gear 66 on one end which meshes with one of the bevel gears 67, 67, on the horizontal shaft 68. This shaft is mounted in bearings 69, 69, alongside the chain support 2, and a spur gear 70 thereon meshes with the spur pinion 71 on the countershaft 72. The countershaft 72 is rotatably mounted in bearings 73, 73, and has a spur gear 74 on one end which meshes with the spur pinion 75 on one end of the shaft 76. The shaft 76 is rotatably secured in bearings 77, 77, and is provided with a spur gear 78 which meshes with the spur pinion 79 on the armature shaft 80 of the Both of the i &

In the modified construction shown, in

Figs. Sand 9 the reeling machine, which is of the same construction as that of Figs. 1- and 2, is driven through an endless belt 5O by a reversible driving motor, not shown. In this construction the draw chain is not endless, as in the preceding figures,

but (as is shown in Figs. 8 and 9) one end of the chain, which is mounted in a chain support 2" of a construction similar to that shown in Figs. 1 and 2, is connected to one end of the piston rod 14 of a fluid pressure cylinder 84. The cylinder 84 extends lengthwise at one end of the chain support 2 with its piston rod 14 in alinement with the draw chain, and tie rods 85, 85, are employed to fasten the end of the cylinder to the end of the chain support 2. The draw chain of the apparatus shown in Figs. 8 and 9, which is made up of links 6 and 7, and pins 8, passes over an anti friction roller 86 at the front end of the draw chain which is secured in bearings beneath the chain support, and the free end of the draw chain extends downwardly .into the pit 87 provided below the chain support for that purpose.

The operation of my improved apparatus Wlll now be described. The tube blanks 18 to be drawn are pointed on the front or forwardend thereof, preparatory to the drawlng operations, so as to insure the readyentrance of this end of the tube blanks into the opening in the drawing die 52, at the beginning of the drawing operations. With the apparatus of Figs. 1 and 2 the guidinggcover 20 1s moved into open position (shown by dotted lines in Fig. 3) and the tube blank 18 to be drawn withthe mandrel 12 inserted therein is placed within the V-shaped groove 1n the upper face of the draw chain, with the flange 15 on the rear-end of the mandrel rod 12 within the recessed slot 11 in the chain link 9. The guide or cover 20 is then lowered into its closed position (shown by full lines" in Fig. 3) so as to bring the V-shaped groove 25 in the wearing plate 24 within the cover 20 closely adjacent to the surface of the tube blank. The locking bar 30 is then shifted, by the handle 34, into the position shown in Fig. 4 so as to bring the locking bar 1nto engagement with the lugs 28 on the cover 20 and lock this guiding cover in closed position. The reversing motor 81 is then started in operation so as to move the upper strand of the endless draw chain counter-clockwise or from right to left in Fig. 2. When the motor is started the belt 50 rotates the reeling machine. The pointed end of the blank to be drawn will by engage ment with the end of the mandrel, prevent the mandrel 12 from moving lengthwise in the tube blank 18 at the commencement of the tube drawing operation, and as soon as the reduction of the tube commences, the front end of the tube 18 will be forced into tight engagement with the mandrel 12. When the movement of the chain is started the tube blank 18 and the mandrel 12 therein, are pushed through the die 52 in the die block 51, and the advancing drawn end of the tube blank enters between the reeling rolls 35 of the reeling machine and is reeled thereby so. as to slightly increase the diameter of the tube. On account of the location of the'= reeling inachine relative to the drawing die 52 the blank or tube is being reeled on one drawn portion thereof simultaneously with drawing an adjoining portion thereof, so that by, the time the tube is pushed entirely through the drawing die 30 practically the entire length of the tube will also be reeled. The action of the skew rollers 35 on the reeling machine rotates and feeds the blank lengthwise through the reeling machine. The mandrel 12 is made of suflicient length to permit the'blank 18 tostretch on the mandrel in the drawing opera tion, and to enable the rear end of the blank being pushed entirely through the drawing die 52 at the completion of the drawing operation by the pushing action of the chain. In this way sticking of thetubes or tube blanks in the die is avoided and overcome.

The motor 81 is then reversed so as to move the top strand of the chain from left to right inFig. 2, andwithdraw the mandrel 12 from the drawn and reeled blank. The hinged guide .or cover 20 is then moved intothe open position shown by dotted lines in Fig. 3, and the mandrel 12 is removed from the chain. Another tube blank, with a mandrel inserted therein is then placed on the chain in therear of the drawing die 52, when the above described operations are repeated.

In the operation of the modified apparatus shown in Figs. 8 and 9, the reeling machine is started in operation by means of the independent driving motor used with this apparatus. into the position shown in dotted lines in Fig. 3 and a tube blank 18 with a mandrel 12 therein is placed on the chain, withits forward pointed end in proximity to the drawing die 52-, the mandrel 12 being attached by the flange 15 to the link 9 of the chain in the manner which has been described. Fluid pressure is then admitted to the rear end of the fluid pressure cylinder 84 so as to advance the piston rod 14 connected to the link 13 on one end of the chain, and in this way push the tube blank and mandrel through the drawing die 52 and into the reeling machine, the operation of the drawing die and The guiding cover 20 is then movedl l 4 l i l reeling machine on the blank being the same as has been described. As the chain is pushed forwardly on the chain support 2, its free end passes around the flanged idler roller 86 on the front end of the chain support 2 and extends downwardly within the pit 87 beneath the chain support 2. When the tube 18 being drawn has been pushed through the drawing die 52, fluid pressure is admitted to the front or stuffing box end of the fluid pressure cylinder 84 so as to move the piston rod 14 in the reverse direction or from left to right in Figs. 8 and 9. This movement of the piston rod moves the chain backwardly on the chain support 2 and withdraws the mandrel= 12 from the now reeled and drawn tube. The guiding cover 20 is then lifted into open position and the mandrel is removed from the top of the chain. Another 'tube blank 18 having a mandrel 12 therein is then positioned on the chain and the end of the mandrel is attached to the link 9 of the chain when the above described operations are repeated.

The operations as have been described are carried out with successive tubes to draw the tube and reduce it in cross sectional area and to loosen the mandrel within the drawn tube.

The advantages of my invention will be apparent to those skilled 'in the art. The apparatus is simple, is strong and durable, and easily kept in repair. By means of my improved apparatus the tube blanks are simultaneously drawn and reeled to loosen themandrel within the drawn tube so that the mandrel can be withdrawn from the reeled tube immediately upon the completion of the drawing operation, instead of requiring a. separate and independent reeling operation to loosen the mandrel in the drawn tube. By pushing the tube blanks through the drawing die, the percentage of reduction in cross sectional area of the blank, in any one pass, can be very materially increased so that the number of drawing steps necessary to reduce a tube blank to the desired size and gage is lessened and the cost of drawing the tubes correspondingly decreased. lhe provision of the guiding cover on the chain-support prevents bending of the tube blank and mandrel, and enables the tube to be pushed through the drawing die.

Modifications in the construction and arrangement of parts may be made without departing from my invention asdefined in the appended claims.

I claim 1. Apparatus for drawing tubes compris-. ing a chain support having a die positioned at one end thereof, a positively driven tube supporting chain movably mounted on said support, means for detachably engaging the chain and the rear end of a tube positioned on the chain to push the tube through said rear end of a tube positioned on the chain to ing operation.

die when said chain is actuated, and means for preventing bending of the tube in pushing the tube through said die.

2. Apparatus for drawing tubes comprising a chain support having a die positioned at one end, a positively driven tube supporting chain movably mounted on said support, means for detachably connecting the chain with the rear end of a tube positioned on the chain to push the tube through said die, means for preventing bending of the tube in pushing the tube through the die, and means operatively connected to the chain for reciprocating said chain on the chain support.

3. Apparatus for drawing tubes comprising'a chain support'having a drawing die at one end thereof, a positively driven tube supporting chain movably mounted on the chain support, means for detachably connecting the chain with the rear end of a tube positioned on the chain to push said blankthrough said die, and a guide above the chain on said chain support, said guide and chain support being arranged to embrace a tube positioned on said chain'to prevent bending of the tube when being pushed through the drawing die in the tube drawing operation.

4. Apparatus for drawing tubes comprising a chain support having a drawing die at one end thereof, a positively driven tube supporting chain movably mounted on the chain support, said chain having a groove in its upper surface to seat the tube thereon, means for detachably connecting the chain with the push said tube through the drawing die, and a guide on said chain support to preventbending of the tube during the tube draw- 5. Apparatus for drawing tubes comprising a chain support having a drawing die at one end thereof, a positively driven tube supporting chain movably mounted on the chain support, means for detachably connecting the chain .with the rear end of a tube positioned thereon to push said tube through the drawing die, and a guide hinged on said chain supportand arranged to swing into and out of position above the chain to prevent bending of the tube in pushing the tube through; the drawing die.

6. Apparatus for drawing tubes comprising a chain support, a drawing die atone end of said support, a positively driven tube supporting chain on said support, said chain supporting chain on said support, a mandrel,

PPE ZZ Q S i911,.drawingntubes-eompris ing a chain support, a drawing die at one endof said support, a positively driven tube supporting chain 'on said support, a mandrel on said chain, means for actuating the chain to push a tube mounted on said mandrel through said drawing die, a reeling ma chine on the exit side of said drawing die, means for actuating said reeling machine to reel the tube and release the mandrel coincident with the drawing operation, and a stripper on the exit side of the reeling machine to prevent backward movement of the reeled tube in withdrawing the mandrel from the reeled tube. v

9. Apparatus for drawing tubes comprising a chain support having a die positioned at one end thereof, a positively driven tube supporting chain movably mounted on said support, and means for detachably engaging the chain and the rear end of a tube p0 sitioned on the chain to push the tube through said die when said chain is actuated.

10. Apparatus for drawing tubes comprising a chain support having a drawing die at one end thereof, a positively driven tube supporting chain movably mounted on the chain support, said chain having a groove in its upper surface to seat the tube thereon, means for detachably connecting the chain with the rear end of a'tube positioned on die, of means on sairisupportiornpushing a tube throiigh thefdie and reeling machine, and means for preventing bending of the tubewhile being pushed through said die and reeling machine.

12. In apparatus for drawing tubes the combination with a horizontal support having a die on one end thereof, and a reeling machine on the exit side of said drawing die, of a tube supportingchain on said support having means to engage and push a tube supported thereon through the die and reeling machine, and means for preventing bending of the tube on said supporting chain in pushing the tube through the die and reeling machine.

13. In apparatus for drawing tubes the combination with a horizontal support having a die on one end thereof, and a reeling machine on the exit side of said drawing die, of means on said support for pushing a tube through the die and reeling machine, and a swinging guide forpreventing bending of the tube while being pushed through said die and reeling machine.

In testimony whereof I have hereunto set my hand.

JOHN W. OFFU'IT.

Witnesses:

A. G. WILSON, G. E. MoYEn. 

